    function welfare=welfare_solver_ces(V_k,D,X,lambda,beta,gamma,theta,rho,t_k,s_k,K)
    s_k_app=[0;s_k];
    model_output=gfop_soe_ces_solver(V_k,D,X,lambda,beta,gamma,theta,rho,t_k,s_k_app,K);
    welfare=model_output.welfare;
    welfare=-welfare;
    end
